Safe boost level

[bjytech]

According to cummins 1250°F pre-turbo is max safe sustained temp.

[Wild and Free]

That and one has to figure in a +- accuracy of the pyro as well. On my 02 I would pull her @ 1300+-50 constant for 50 miles a lot of times and never an issue.

[Wild and Free]

I just towed back to Colorado from Oklahoma at gcvw... ish... and there were a lot of hills that were solid 3rd gear hills with 50kt winds. I didn't get to stay in OD until the Temps dropped to 60f in Colorado on the flats along I70.

What I want to know is what EGT is the max safe continuous temp.

 

 Were you driving or flying?...............come down out of the clouds man...............50kt winds.

If you were on a boat or in the sky you can use those terms on land please use mph...........

[CSM]

LoL. All wind is knots to me now... we use Celsius too for all our performance calculations.

[diesel4life]

For towing, cajflynn always used to say keep our under 20 and don't tow fast. Seemed top work.

 

It would be awfully hard to keep under 20 psi under certain conditions, I.E. steep grades towing at freeway speeds. I don't drag race to the top by any means, but I've always felt its safer to keep with the general flow of traffic then slowing down to the point of possibly creating a hazard.

 

How do you like towing with your new injector/turbo combo? Im sitting on the same set up, just haven't had the time to tear the truck down and do the swap. Im hoping in the next few weeks to get it done.

[CSM]

It would be awfully hard to keep under 20 psi under certain conditions, I.E. steep grades towing at freeway speeds. I don't drag race to the top by any means, but I've always felt its safer to keep with the general flow of traffic then slowing down to the point of possibly creating a hazard.

 

How do you like towing with your new injector/turbo combo? Im sitting on the same set up, just haven't had the time to tear the truck down and do the swap. Im hoping in the next few weeks to get it done.

 

I don't care much about the other traffic as long as I am going the minimum legal speed.  Jerks will be jerks and I can't see them behind my trailer.  If people get road ragey... then I will just slow down and stop.  If they want to play stupid games I have stupid prizes for them.

 

Overall feel...

I like towing with it.  I REALLY like driving it around town.  I have an automatic, which I personally like since the truck is 90% a daily driver.  However, it has a bit of a big step between the gears and at my weight I was accelerating slow or holding it down a gear and not shifting until 25-2600 to keep from losing spool, Overall it does well as long as I keep an eye on temps.  My trans is tight and the torque converter has a pretty low stall. If I dialed down the smarty I think it would require a bit less attention.  

 

Drivability numbers and my techniques.

 

At 70+ degrees ambient temp, the EGTs will be happy above 1800RPM and I can see 10-30 PSI with comfortable EGTs as well.  Below 60 degrees ambient temp, the intercooler really gets more efficient and the truck moves quite well as I could definitely tow faster, but the mileage suffered.  The truck is smooth, and can pull, but with the smarty I have to pay attention not to lug it, as it has the power to pull down low, but the EGTs will soar until the RPMs get up.  

 

The below trailer has the aerodynamic coefficient of a smartly thrown anvil and total weight was 21k.  I was locked up in 3d with most of the trip going fairly slow.  Once I hit I-70, I started to get in a bit more of a hurry and sped up from 55-60 and got away from the 50 KNOT (57 mph) gusty headwind.  I sped up to 65mph and it would pull that load locked up in OD on level ground or a very slight grade with 20psi and 1050-1150 F EGT depending on grade in cruise. Unfortunately, I averaged 13mpg at 55mph but was down in the 9-10 range at 65mph, especially in the wind.  

 

At 65 in 3d, I would see 800-1000F EGT and 17-24psi.  I found the "happy" speeds were 45-60 in 3d regardless of the hill, and 65+ in OD with the goal at both speeds to stay below 1150F and around 20psi.  I could pull the load in OD but not without getting above those temps when driving below 65mph... if I had shorter tires I might be able to do it, I was only 200 rpm out of the sweet spot.  I found that if the EGT was 800-850 I could shift to OD and the temps would stay below the 1150 i set as my personal continuous max.  

 

If I wanted to go faster, it would have done it.  I could have been at 75mph quite easily and would have been in the horsepower band with happy turbo and EGTs.  However, I didn't make a ton of power until the boost came in at 1600-1800 rpm or so. The power holds strong as high of RPM as I've had it, which is around 2700rpm.  

 

Edited May 10, 2015 by CSM

[Wild and Free]

CSM, I missed where you got a trailer, I knew you were looking, did you buy that one/ details man we need details..........

I just looked at your rigs details, 1400 stall holy hell man that thing must suck to drive, good thing you have a smarty comp stack and quick spooling turbo with enough fuel or you would never get spooled up with that tight of a converter. Who in the heck sold you a converter with a stall that low?  In the diesel world 1600-1800 is a fairly low stall.

That would be a good stall speed with 235 tires and 4.56 gears.

[Mopar1973Man]

I don't care much about the other traffic as long as I am going the minimum legal speed.  Jerks will be jerks and I can't see them behind my trailer.  If people get road ragey... then I will just slow down and stop.  If they want to play stupid games I have stupid prizes for them.

 

  Absolutely.

 

As stated by Idaho...

 

 

49-655.  Minimum speed regulation. No person shall drive a motor vehicle at such a slow speed as to impede the normal and reasonable movement of traffic except when reduced speed is necessary for safe operation or in compliance with the law.

 

 

49-639.  Turning out of slow moving vehicles. On a two-lane highway outside an urban area where passing is unsafe due to oncoming traffic or other conditions, the driver of a vehicle traveling slower than the normal speed of traffic and behind which three (3) or more vehicles are formed in line, shall turn off the roadway at the nearest place designated as a turnout or wherever sufficient area for a safe turnout exists, in order to permit the following vehicles to pass.

 

As for Instate travel I'm not fond of the 80 MPH speed limits now. Even empty truck it just way too fast for my blood and the truck my MPG's are way low at those speeds. Not fond of running the tach at 2,300 RPM's just not efficient for my rig at all.

 

CSM as for your EGT's and such is because of the 4 speed gears ratios. Your overdrive is lower ratio than my 5 speed (0.75) or even a 6 speed (0.73). But when you drop back to 3rd or out of over drive your back to direct (1:1) ratio. Just like when I drop from 5th to 4th is the same thing I get direct (1:1).

[CSM]

Bill, I will add it to my garage... 

 

I ordered a Cargo Craft from the guys at Central Trailer in Broken Arrow, OK.  28' box, 7'6" high inside, 8'6" wide.  7k dexter axles with brakes on all 4 chrome wheels.  Cost 8600 and took a month to get from the factory.

 

It has LED lights, what look like 3/4 plywood walls 2x3/4 floor It has "rv style" wiring to the lights inside to a central switch of truck power. big escape door on the drivers side and the door you see on the passenger side.  

 

It weighs about 4000 lb empty.  

 

I added a CURT Trunnion style equalizer hitch to the truck and a set of AirLift airbags and the trailer tows great... even in a tornado watch and severe thunderstorm in Oklahoma!  It is blown a bit, but not awful as long as I keep my speed down to a sane level.  I ran 43 lbs in the airbags and the 1400 lb rated equalizer about half way tight.  

Edited May 10, 2015 by CSM

[CSM]

CSM, I missed where you got a trailer, I knew you were looking, did you buy that one/ details man we need details..........

I just looked at your rigs details, 1400 stall holy hell man that thing must suck to drive, good thing you have a smarty comp stack and quick spooling turbo with enough fuel or you would never get spooled up with that tight of a converter. Who in the heck sold you a converter with a stall that low?  In the diesel world 1600-1800 is a fairly low stall.

That would be a good stall speed with 235 tires and 4.56 gears.

 

I am the guy who spec'ed it out and you are right.  It isn't the best converter to tow with.  I may change it when i pull the motor next year for a checkup & hopefully cam.  

 

However, it drives real nice empty and once you get the trailer past 10mph it works good. 

[diesel4life]

If one doesn't feel safe traveling the posted speed limit (or at least within 5-10mph) then the best and safest option is simply choose another route. Ive seen enough rear end accidents on the local freeway here to firmly believe that. If your traveling 15mph under the posted limit and the rest of the world is realistically doing 10-20 over, its a recipe for disaster. Only a matter of time before someone not paying attention happens along.

There have been instances where my load dictated that 70mph was not practical so I stayed off the freeway and stuck to the 2 lane highways. It takes a little longer but I'll take going with the general flow of traffic over driving out of my rear view mirror any day.

[Mopar1973Man]

Like myself I'll run the trucker speed limit at 70 MPH which is like 2,100 on the tach. But it so rare to be near an interstate. I'm mostly running state highway and 2 lane roads with speed limits of 45 MPH to 65 MPH. Towing my RV I typically keep my speed to 55 MPH with all the 2 lane highways. I used to jump on the interstate with the RV and run 65 MPH with the truckers. But now with the 70 MPH trucker speeds I'll just avoid the interstates. There is plenty of wonderful state highway to travel and slower more relaxed speeds.

 

Being I've seen plenty of accidents on the highway with the fire dept. I tend to drive under the speed limit most of the time with heavy loads. Gives more timee for me to react to idiots passing too many vehicles.

 

Take the time and watch some of the YouTube videos of vehicle accidents or car crashes. You'll see most of the video a common mistake of people passing other vehicles and either collide with on coming or lose control making the pass at too high of speed or too tight and loose control.

[Wild and Free]

Just got home from Rapid city SD yesterday and while down there saw my first ever 80MPH speed limit signs on the interstate there. ND still has 75 mph limit.